Heart rate monitor



FIG. 1 is a top perspective view of a heart rate monitor shown without the monitor unit for the completeness of the illustration;

FIG. 2 is a top perspective view of the heart rate monitor;

FIG. 3 is a front view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is a fragmental top plan view thereof;

FIG. 6 is a fragmental back plan view thereof;

FIG. 7 is an exploded perspective view thereof; and,

FIG. 8 is a top perspective view thereof shown in a condition of use.

The broken lines in the FIG. 6 are included for the purpose of illustrating portions of the heart rate monitor that form no part of the claimed design, and all other broken lines in the drawings represent the environmental subject matters. None of the broken lines form a part of the claimed design. 

The ornamental design for a heart rate monitor, as shown and described. 